Similar types of fuzes are previously known in the art. The trajectory safety is intended to activate the arming igniter within a trajectory safety distance which may be selected at between 50 and 150 meters from the muzzle of the gun. The trajectory safety device may receive activation in conjunction with the movement in the barrel of the gun, for example with the aid of induction, and in addition the trajectory safety contact operates with a certain time lag which ensures the above-mentioned trajectory safety distance. The trajectoy safety device may also be activated mechanically by the acceleration which occurs in conjunction with firing of the gun. The arming igniter may be of that type which utilizes a locking pin which locks the slide to a fixed portion in the ammunition unit on the movement thereof in the trajectory safety region. The pin is displaced from its engagement with the fixed portion or the movable portion with the assistance of an ignition charge which may be activated by means of the above-mentioned electric trajectory safety device. The initiation detonator may also be electrically initiated. on activation of the arming detonator, the movable portion (the rotor) executes an instantaneous movement during a few milliseconds when the detonation cap is moved to its arming position in register with the initiation detonator which may be activated by means of the impact contact or the like. The electronics of the fuze, like the design of ignition charges, contacts etc. are previously known in the art.